Host David Letterman actually challenged guest Al Gore about his recent sale of Current TV to al Jazeera saying, “So you, Al Gore, are doing business with this country that's enabling your ultimate foe of climate change” (video follows with transcript and commentary):

DAVID LETTERMAN, HOST: So now let's talk about Current TV. It's a network I never could find it. (Laughter) What were your hopes for Current TV when you launched your own network?

AL GORE: Well, to have an independent voice for news and information, and my partner Joel Hyatt and I accomplished a lot. I'm very proud of what we did. We won every single award in television journalism, but it turns out to be very tough for an independent network to compete in an age of conglomerates. And so it was time to make a move. I'm very proud that al Jazeera is going to have the opportunity to give high quality news throughout the country. They've won awards all over the world, very highly-respected.

LETTERMAN: Now why do we think of al Jazeera as something not right going on there in terms of, in terms of the good for Americans? Why do we think that they may be propaganda for Muslim violence and terrorism?

GORE: Well, it's certainly not. And many years ago it put some videos on in the Arabic version that I think were misinterpreted, but the al Jazeera English and now al Jazeera America really high quality stuff. They're very widely respected, and people see for themselves. And, by the way, their climate coverage is higher quality and more extensive than any network on TV now in the U.S.

LETTERMAN: Who, al Jazeera, what does that mean, al Jazeera?

GORE: I'm not sure. I ought to know, but I don't know. (Laughter) Wait a minute I can Google it. Just like Dr. Oz. (Laughter)

LETTERMAN: I was told earlier I think it means "the island." I'm not sure what that reference is. But what country is the origin of al Jazeera?

GORE: Qatar.

LETTERMAN: And that's …

GORE: Gas and oil.

LETTERMAN: Gas and oil. So you're selling this television network to a gas and oil supported emirate. It’s not an emirate, it’s an independent country.

GORE: One of the emirates. It's independent. And the closest ally of the U.S. In the Arab world. Our fleet is there.

LETTERMAN: Isn't that one of the problems with global warming, our dependence on petroleum-producing countries?

GORE: Yes, it is. And they have…

LETTERMAN: So you, Al Gore, are doing business with this country that's enabling your ultimate foe of climate change.

GORE: I think I understand what you're getting at, Dave, (Laughter) but I disagree with it. First of all, they have ambitious plans to develop renewables in the region. There's a visionary plan to take solar energy and wind energy from the Middle East and North Africa to Western Europe. Again, the network that they founded has become a very widely respected news-gathering organization, including on climate issues.

LETTERMAN: Yeah, see if you can get Regis a show.

GORE: I’ll suggest that.

What was truly fascinating about this segment was Letterman was tougher on Gore than Steve Kroft was on President Obama and Secretary of State Hillary Clinton on Sunday's 60 Minutes.

The folks at CBS must be pleased that their late night comedy talk show host is actually a better journalist than one of the anchors on their flagship prime time news magazine.